| abstract |
A process for the preparation of derivatives of oxamic acid, of the formula **(See formula)** in which R is -OH, lower alkoxy or an amine radical, A is a member chosen from the group consisting of 3-pyridyl, 2-pyridyl when R is other than ethoxy, 4-pyridyl, 2-pyrazinyl and 2-pyrimidinyl, 2-cyanophenyl, 3-fluorophenyl, 4-phenylazophenyl, 4-carbamylphenyl, 2-nitro-4-trifluoromethylphenyl, 2-cyano-3-methoxyphenyl, 4-nitro-3-trifluoromethylphenyl, 5-chloro-2-sulfamoylphenyl and **(See formula)** in which R1 is a member chosen from the group consisting of hydroxyl, lower alkoxy, and amine radicals; R2 is a member chosen from the group consisting of hydrogen, lower alkoxy, halogen, and phenoxy-lower alkoxy; R3 is a member chosen from the group consisting of hydrogen, lower alkoxy, chlorine, fluorine and nitro; and R4 is a member chosen from the group consisting of hydrogen and lower alkoxy; with the proviso that one of R2, R3 and R4 is other than hydrogen, characterized by reacting by coupling an amine of the formula ANH2 with a reactive compound ZCOX, where Z represents an amine reactive group chosen from the group consisting of hydroxyl, halogens, azido, diazotate and steric active fractions; and X represents a group capable of becoming -CO2H, -CO2R5, (see formula), chosen from -CH = CHCOZ, -C (OR5) 3, -CH (COR5) 2 or -COZ, where R5 is lower alkyl, cycloalkyl or aralkyl. (Machine-translation by Google Translate, not legally binding) |